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United States Patent |
6,168,415
|
Pleasant
,   et al.
|
January 2, 2001
|
Baffle
Abstract
A mold insert for an injection molding machine has a circumferential liquid
conduit groove and a plurality of liquid-receiving bores extending
inwardly from the groove. Baffles are removably inserted into the
liquid-receiving bores and have heads located in locking engagement with
the sidewalls, including the undercut portions thereof, to retain the
baffles in their respective liquid-receiving bores. Each baffle has a
blade that fits snugly within a liquid-receiving bore to separate the
liquid-receiving bore into a liquid inlet passageway and a liquid outlet
passageway. Fins project outwardly from opposite faces of the blade to
create turbulence in liquid flowing into and out of the liquid-receiving
bore, which enhances cooling (or heating) of the mold insert. The baffle
is also useful with other solid components having a liquid conduit for
cooling purposes and a transverse liquid-receiving bore intersecting the
liquid conduit. An improved liquid barrier for use in preventing the flow
of liquid in the liquid conduit groove is formed by a dam member
substantially identical to the head of a baffle.
Inventors:
|
Pleasant; Ronald E. (Kenton, OH);
Lafferty; H. Eugene (Belle Center, OH)
|
Assignee:
|
Pleasant Precision, Inc. (Kenton, OH)
|
Appl. No.:
|
184367 |
Filed:
|
November 2, 1998 |
Current U.S. Class: |
425/552; 138/38; 138/42; 249/79; 425/192R |
Intern'l Class: |
B29C 045/73 |
Field of Search: |
425/547,552,190,192 R
249/79
138/38,40,42
|
References Cited
U.S. Patent Documents
2688986 | Sep., 1954 | O'Brien | 138/42.
|
3692064 | Sep., 1972 | Hohnerlein et al. | 138/42.
|
3924653 | Dec., 1975 | Bendixen | 138/42.
|
4200149 | Apr., 1980 | Pechner | 138/42.
|
4828479 | May., 1989 | Pleasant | 425/192.
|
4959002 | Sep., 1990 | Pleasant | 425/192.
|
4966544 | Oct., 1990 | Mitake | 425/552.
|
5053200 | Oct., 1991 | Schaeffer et al. | 138/42.
|
5261806 | Nov., 1993 | Pleasant | 425/144.
|
5647114 | Jul., 1997 | Pleasant | 425/192.
|
Foreign Patent Documents |
3-124420 | May., 1991 | JP.
| |
WO 94/09961 | May., 1994 | WO.
| |
Other References
P. L-17 of 1986 Product Catalog, published by D-M-E Company, Madison
Heights, MI, 1986.
Front sheet and p. D-13 for Dec. 1995 Price List published by PCS Company,
Fraser, MI, Dec. 1995, admitted to show prior art baffle.
|
Primary Examiner: Davis; Robert
Assistant Examiner: Leyson; Joseph
Attorney, Agent or Firm: Dybvig; Roger S.
Parent Case Text
CROSS REFERENCE TO RELATED APPLICATION
This application is a division of copending Application Ser. No.
08/716,506, filed Sep. 18, 1996, now U.S. Pat. No. 5,830,515, dated Nov.
3, 1998.
Claims
Having thus described our invention, we claim:
1. A baffle for use in cooling or heating a solid component, said solid
component having a liquid-receiving bore extending transverse to and
opening to a liquid conduit formed in said component, said baffle
comprising:
a blade adapted to be received within said liquid-receiving bore, said
blade having a width substantially equal to the width of said bore so that
said blade would, if inserted into said bore, divide said bore into a
liquid inlet passageway and a liquid outlet Passageway by said blade so
that liquid flowing into said liquid inlet Passageway would flow into said
liquid outlet passageway around the end of said blade at the innermost end
of said bore;
a plurality of first fins projecting outwardly from a first face of said
blade for restricting flow of liquid through said liquid inlet Passageway,
each of said first fins having a first margin connected to said first face
that extends parallel to said first face, said first margin extending from
a side edge of said first face and spaced from the opposite side edge of
said first face, alternate ones of said fins extending from respective
opposite side edges of said first face; and
a plurality of second fins projecting outwardly from a second, opposite
face of said blade for impeding flow of liquid through said liquid outlet
Passageway, each of said second fins having a first margin connected to
said second face that extends parallel to said second face, said first
margin thereof extending from a side edge of said second face and spaced
from the opposite side edge of said second face, alternate ones of said
second fins extending from respective opposite side edges of said second
face.
2. The baffle of claim 1 further comprising a head located at one end of
said blade, said head being threaded for engagement with a wall of said
liquid conduit.
3. The baffle of claim 1 wherein said first margin of each of said fins is
linear, and wherein each of said fins is wedge-shaped having a second
linear margin intersecting said first linear margin, said first and second
linear margins connected by a third, outer margin, and wherein the second
linear margin of each of said fins extends outwardly from the face of said
blade to which the first linear margin thereof is connected, and the
third, outer margin of each of said fins extends from the intersection of
the first linear margin thereof with a side edge of said blade to the
second linear margin thereof.
4. The baffle of claim 3 wherein the third, outer margin of each of said
fins is arcuate.
5. The baffle of claim 4 wherein each of said fins projecting from the
first face of said blade is aligned longitudinally with a corresponding
fin projecting from the second, opposite side of said blade, and wherein
the third, outer margins of the longitudinally-aligned fins extend from
respectively opposite side edges of said blade.
6. The baffle of claim 5 wherein the fins projecting from each face of said
blade are located at mutually longitudinally spaced locations, and wherein
the third, outer margins of the mutually-spaced fins on each face of the
blade extend from alternating side edges of said blade.
7. The baffle of claim 6 wherein adjacent, mutually-spaced fins projecting
from the first face of said blade and the corresponding aligned fins
projecting from the second, opposite face of said blade together with said
blade appear, from an end of said baffle, to substantially form a circle.
8. A baffle for use in a mold insert for an injection molding machine, said
mold insert having a liquid-receiving bore extending radially inwardly
from a circumferential liquid conduit groove formed in said mold insert,
said baffle comprising:
a body adapted to be received in a liquid-receiving bore; and
a head connected to said body, said head having a size and shape to
substantially block the flow of liquid in a liquid conduit groove when
said body is received in said liquid-receiving bore, thereby directing
said flow into said liquid-receiving bore, said head further being adapted
for engagement with an undercut portion of said liquid conduit groove to
releasably lock said baffle in position with said body received in said
liquid-receiving bore, said head having first and second faces and first
and second opposed side margins, said head having a first recess formed in
the first face thereof adjacent the first side margin thereof, and said
head having a second recess formed in the second face thereof adjacent the
second side margin thereof, wherein said recesses cause the material
forming said head surrounding said recesses to be resilient.
9. The baffle of claim 8 wherein said head further has a third recess
formed in the second face thereof adjacent the first side margin thereof
and a fourth recess formed in the first face thereof adjacent the second
side margin thereof, and wherein said third and fourth recesses are
laterally offset from said first and second recesses, respectively.
Description
FIELD OF THE INVENTION
This invention relates to an improved mold insert and an improved baffle
for use therewith. This invention also relates to an improved liquid
barrier for use in a mold insert. Mold inserts of the type to which this
invention pertains are used in machines for injection molding plastic
workpieces, but this invention may be useful in other fields, such as die
casting and rubber molding.
BACKGROUND OF THE INVENTION
This invention is intended for use with mold inserts of the type shown in
U.S. Pat. No. 4,828,479, granted May 9, 1989 to Ronald E. Pleasant, and
U.S. Pat. No. 4,959,002, granted Sep. 25, 1990 to Ronald E. Pleasant, the
disclosures of which are hereby incorporated herein by reference. The '479
and the '002 patents disclose generally cylindrical mold inserts for
injection molding machines which have a generally cylindrical liquid
channel section with a liquid conduit groove extending circumferentially
around the liquid channel section. A liquid, such as water, is circulated
around the mold insert in the liquid conduit groove for cooling (or
heating) portions of the mold insert. A liquid barrier is located in the
groove so that the groove is double-ended, one end constituting a liquid
inlet end and the other end constituting a liquid outlet end. A mold
machine with which an insert is used has inlet and outlet connectors
aligned with the inlet and the outlet ends of the groove so that the water
or other liquid can be introduced into the liquid conduit groove.
It is known in the art to provide blind bores, by drilling for example,
that extend radially inwardly from the liquid conduit groove and receive
liquid to meet various cooling (or heating) needs. A simple baffle
comprising a flat blade fitted to the diameter of a liquid-receiving bore
may be inserted centrally therein to separate the bore into an inlet
passageway and an outlet passageway. Typically, the blade is formed from
brass, aluminum, or stainless steel, and a portion of the blade extends
into the liquid conduit groove to divert liquid flowing in the groove into
the inlet passageway formed by the blade. The blade does not extend to the
bottom of the bore so that liquid diverted into the inlet passageway of
the bore may flow around the bottom of the blade to the outlet passageway
and back into the liquid conduit groove.
A simple, blade-only baffle, as described above, has a tendency to move or
shift from its central position in the liquid-receiving bore due to
pressure from the flowing liquid. This shifting of the baffle within the
bore can create imbalanced flow characteristics which negatively impact
the cooling (or heating) action provided by use of the baffle. To prevent
shifting of the baffle within the bore, a so-called "spiral" baffle may be
used in place of a blade-only baffle. A spiral baffle remains centered
within its bore due to the body thereof having a generally cylindrical
shape that fits snugly within the bore, thereby providing multiple
circumferential engagement points with the bore. Spiral baffles also
provide better cooling (or heating) action than straight baffles as a
result of longer passageways for the liquid flowing through the bore
created by use of a pair of drill-like, helical or spiral grooves in the
baffle body. The helical or spiral grooves result in a spiral liquid inlet
passageway and a spiral liquid outlet passageway in the liquid-receiving
bore. The spiral baffle is similar to a straight baffle in that it does
not extend to the bottom of the liquid-receiving bore. Therefore, liquid
diverted into the bore may flow into the spiral inlet passageway and out
of the spiral outlet passageway. A similar effect has been obtained by
twisting a simple, blade-only baffle to create a longer, spiral path for
the liquid.
Such prior art baffles, although commonly used, are not particularly suited
for use with mold inserts of the type shown in the aforementioned '479 and
'002 patents because no suitable way to positively secure the baffles into
the liquid-receiving bores of mold inserts was heretofore known. The prior
art baffles are typically retained in the bores merely by the frictional
engagement of the baffle with the bore. In addition, although prior art
baffles provide generally acceptable cooling (or heating) action, better
cooling (or heating) action is desired.
The liquid barrier mentioned above is typically formed by a dam member that
is either welded in place in the liquid conduit groove or is secured in
the liquid conduit groove by the use of a pair of locking members that are
advanced through a pair of outwardly-extending bores in the dam member and
into engagement with the inwardly-facing surfaces of undercut portions of
the groove sidewall, as illustrated and described in commonly owned
international application, International Publication Number WO 94/09961,
published May 11, 1994, and U.S. patent application Ser. No. 08/387,250,
filed Feb. 13, 1995, now U.S. Pat. No. 5,647,114, which are hereby
incorporated herein by reference.
In addition to or in place of the liquid-receiving bores described above,
the user of a mold insert may, in order to meet various cooling (or
heating) needs, drill liquid passageways extending inwardly of the
circumferentially-extending liquid conduit groove and opening at
mutually-spaced locations in the liquid conduit groove. To insure an
adequate flow of liquid into such inwardly directed passageways, one or
more additional dams or barriers are affixed inside the peripheral liquid
conduit groove between the mutually-spaced openings of each liquid
passageway. The provision of additional dams or barriers, by either
welding or the use of locking members as described above, can be time
consuming and costly. Accordingly, there exists a need to enable the user
of an insert to quickly, accurately and securely assemble liquid dams or
barriers into liquid conduit grooves of mold inserts.
SUMMARY OF THE INVENTION
An object of this invention is to provide an improved baffle for use in
cooling (or heating) solid components, such as mold inserts for injection
molding machines, by passing a liquid therethrough. A more particular
object is to provide such an improved baffle wherein turbulence is created
in the liquid flowing around or past the baffle to enhance the cooling (or
heating) action of the liquid.
Another object of this invention is to provide an improved baffle
particularly suited for use in mold inserts for injection molding
machines. More particularly, an object of this invention is to provide a
self-retaining baffle for use in a mold insert that is readily secured in
and removed from a liquid-receiving bore provided in the mold insert.
A further object of this invention is to provide a baffle in accordance
with the foregoing objects that is durable and that can be easily and
inexpensively manufactured.
Another object of this invention is to provide a baffle that achieves the
foregoing objects which can be used with existing mold inserts without
modification thereto.
Still another object of this invention is to provide an improved mold
insert and a method for assembling the same wherein baffle members
provided in liquid-receiving bores are self-retaining and are easily
locked into and removed from the liquid-receiving bores.
An improved baffle in accordance with this invention includes a flat blade
adapted to be snugly received in a liquid receiving bore which extends
transverse to a liquid conduit, for example in a mold insert. The blade
separates the bore into an inlet passageway and an outlet passageway, but
does not extend to the bottom of the bore. A portion of the baffle, which
may be termed the head thereof, extends into the path of liquid flowing in
the liquid conduit so that the liquid is diverted into and through the
liquid-receiving bore. The baffle has plural fins projecting outwardly
from opposite sides thereof into the inlet and outlet passageways. Liquid
flowing in the passageways is partially obstructed by the fins, thereby
creating turbulence in the liquid.
When used in a mold insert having an outwardly-open peripheral or
circumferential liquid conduit groove, the baffle preferably has a head
that blocks the flow of liquid in the groove and diverts the flow into the
liquid-receiving bore. Because the bore is typically of a diameter smaller
than the width of the liquid conduit, the head and blade of the baffle
typically form a T-shape. The liquid conduit groove has sidewalls that are
preferably provided with undercut portions extending alongside the opening
of the liquid-receiving bore. The baffle may be first inserted into the
liquid-receiving bore so that its head does not engage the groove
sidewalls. After the baffle is fully received in the liquid-receiving
bore, the baffle is rotated until the baffle head engages the groove
sidewalls, including the undercut portions thereof, thereby locking the
baffle into position in the liquid-receiving bore.
The head of the baffle may be solid, in which case the baffle is
rotationally held in place by simple frictional engagement of the head
with the undercuts. Alternatively, the head may include hollowed-out
portions or recesses that give the head resilient characteristics. The
recesses are collapsed by the engagement of the head with the groove
sidewalls as the head is rotated. When the baffle is fully rotated into
position, the resiliency of the head serves to clamp the baffle in place.
The baffle may also be driven into place, without rotation, by use of a
suitable tool such as a hammer.
Each of the baffle fins is preferably wedge-shaped and is aligned
longitudinally with a corresponding wedge-shaped fin projecting from the
opposite face of the baffle blade. The longitudinally-aligned fins have
outer margins that extend from opposite side edges of the baffle blade.
Similarly, the outer margins of mutually-spaced, adjacent fins on each
face of the baffle blade extend from respectively opposite side edges of
the baffle blade. The fins are not as wide as the baffle blade, and the
mutually-spaced, adjacent fins on each side of the baffle blade are
laterally offset from one another.
Each fin is preferably shaped so that the outer margin thereof snugly
engages the wall of the liquid-receiving bore. For typical cylindrical
liquid-receiving bores, each of the fins has an arcuate outer margin that
engages the wall of the liquid-receiving bore, although other bore
arrangements may dictate the use of linear wall-engaging outer margins.
Other objects and advantages will become apparent from the following
description and the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is sectional view of an improved mold insert in accordance with this
invention taken along line 1--1 of FIG. 2 and showing a baffle in
accordance with this invention secured in a liquid-receiving bore in the
mold insert.
FIG. 2 is a simplified, partially-diagrammatic end view of the mold insert
of FIG. 1 as viewed in the direction of arrows 2--2 of FIG. 1.
FIG. 3 is a perspective view of the baffle in accordance with this
invention illustrated in FIG. 1.
FIG. 4 is a side view of the baffle.
FIG. 5 is an edge view of the baffle as viewed in the direction of arrows
5--5 of FIG. 4.
FIG. 6 is an end view of the baffle as viewed in the direction of arrows
6--6 of FIG. 4.
FIG. 7 is a fragmentary side view as viewed in the direction of arrows 7--7
of FIG. 1 showing a liquid-receiving bore in the mold insert before a
baffle is assembled into the mold insert.
FIG. 8 is a fragmentary side view similar to FIG. 7, but showing an initial
stage of the assembly of a baffle into the mold insert.
FIG. 9 is a view similar to FIG. 8, but showing a later stage of the
assembly process. FIG. 9 is the equivalent of a fragmentary side view as
viewed in the direction of arrows 8--8 of FIG. 1.
FIG. 10 is an enlarged, fragmentary side view of a second embodiment of the
baffle of FIG. 1 showing a modified head thereof.
FIG. 11 is a sectional view as viewed in the direction of arrows 11--11 of
FIG. 10.
FIGS. 12 and 13 are views somewhat similar to FIGS. 8 and 9 and illustrate
the second embodiment of the baffle during the assembly of the baffle into
a mold insert.
FIG. 14 is a fragmentary, sectional view somewhat similar to FIG. 1 showing
the second embodiment of the baffle locked in place in the mold insert.
FIG. 15 is a fragmentary, sectional view of a generic solid component being
cooled (or heated) by a process utilizing a baffle in accordance with this
invention.
FIG. 16 is a side elevational view of a third embodiment of a baffle in
accordance with this invention.
FIG. 17 is a sectional view of the baffle of FIG. 16 taken along lines
17--17 thereof.
FIGS. 18 and 19 are fragmentary side views of a mold insert showing the
baffle of FIG. 16 being inserted into a liquid conduit groove in a mold
insert, the liquid barrier being shown in cross section.
FIG. 20 is a fragmentary view, with parts in cross section, showing the
baffle locked in place in the liquid conduit groove of the mold insert of
FIGS. 18 and 19.
DETAILED DESCRIPTION
With reference to FIGS. 1 and 2, this invention is directed to an improved
mold insert, generally designated 20, for use in an injection molding
machine (not shown) and an improved baffle therefor, generally designated
100. The mold insert 20 may be constructed substantially in accordance
with the '479 and '002 patents mentioned above, but is modified as will be
described below.
The mold insert 20, which may be formed from tool steel or a non-ferrous
metal, such as aluminum, has a generally cylindrical shape and includes a
one-piece body 22 having a cylindrical liquid conduit section 24. Although
the mold insert 20 may have other than a cylindrical shape, further
description herein is directed to a cylindrical mold insert 20. A
peripheral or circumferential liquid conduit groove 26 is provided in the
liquid conduit section 24 extending 360 degrees therearound, and as is
well known, a liquid such as water is directed into the liquid conduit
groove 26 and flows therearound to cool (or heat) the mold insert 20. As
shown in FIG. 1, the liquid conduit groove 26 has opposed sidewalls 28,
each of which has a recess or undercut 30 extending along the entire
length of the groove 26.
Referring to FIG. 2, a barrier or dam assembly, generally designated 31, is
inserted into the liquid conduit groove 26 to substantially block the flow
of liquid in the liquid conduit groove 26, thereby rendering the groove 26
double-ended. The dam assembly 31 corresponds to the barrier section
illustrated and described in the aforementioned '479 and '002 patents. The
dam assembly 31 may be secured into the liquid conduit groove 26 in
accordance with prior art methods, such as illustrated and described in
the aforementioned international application, International Publication
Number WO 94/09961, published May 11, 1994, or other known locking
techniques, such as welding, might be used. However, it is contemplated
that certain aspects of the baffles in accordance with this invention will
be useful in creating improved liquid barriers, as will be described below
in further detail.
With continued reference to FIGS. 1 and 2, four blind bores 32, hereafter
referred to as liquid-receiving bores 32, are provided in the mold insert
20 and extend radially-inwardly from the liquid conduit groove 26
transverse thereto. As is evident from the drawings, the liquid receiving
bores 32 open at circumferentially-spaced locations along the base of the
liquid conduit groove 26. FIG. 2 illustrates the preferred embodiment of
this invention wherein four liquid-receiving bores 32 are provided--one
for each quadrant of the mold insert 20. However, another number of
liquid-receiving bores 32 may be provided, depending on the desired
cooling (or heating) action and the size of the mold insert 20 and the
liquid-receiving bores 32.
The liquid-receiving bores 32 are preferably formed in the mold insert 20
by drilling, but may be formed in any other suitable manner. When the
liquid-receiving bores 32 are provided by drilling, the bores 32 are
typically cylindrical but do have drill points 34 formed at the base
thereof. Although not necessary, the liquid-receiving bores 32 are
typically identical to one another. Therefore, further discussion of this
invention will be limited to a single liquid-receiving bore 32, such
discussion being equally applicable to each liquid-receiving bore 32.
FIG. 1 illustrates the mold insert 20 with a baffle 100 secured in a
liquid-receiving bore 32. Four baffles 100 are illustrated
diagrammatically in FIG. 2. With reference also to FIGS. 3 through 6, the
baffle 100 is preferably formed from molded nylon, which is capable of
withstanding temperatures on the order of 250 to 275 degrees fahrenheit,
although it is contemplated that the baffle 100 may be formed from a
suitable plastic material using a thermal set technique whereby hot
plastic is injected into a cooled mold. The baffle 100 includes a flat
blade 102 that is inserted into the liquid receiving bore 32, the blade
102 being substantially the same width as a diameter of the
liquid-receiving bore 32 so that the blade, when inserted into the bore
32, separates the liquid-receiving bore 32 into an inlet passageway 32A
and an outlet passageway 32B. Preferably, the blade 102 terminates near
the bottom of the bore 32, but does not extend to the bottom of the bore
32. As a result, clearance is provided between the radially-inward end of
the blade 102 and the bottom of the liquid-receiving bore 32.
The baffle 100 also includes a head 104, which may be integrally formed
with the blade 102 to create a T-shape, that is located within the liquid
conduit groove 26. The head 104 of the baffle 100 is so sized and shaped
that it matches the cross section of the liquid conduit groove 26 to
substantially block the flow of liquid therein. As a result, liquid
flowing in the liquid conduit groove 26 is diverted into the inlet
passageway 32A formed in the liquid-receiving bore 32, as illustrated
diagrammatically in FIG. 2. The diverted liquid flows radially-inwardly
through the inlet passageway 32A, through the clearance provided at the
bottom of the bore 32, radially-outwardly through the outlet passageway
32B formed in the liquid-receiving bore 32, and back into the liquid
conduit groove 26. As evident from FIG. 2, this diversion of liquid flow
occurs at each liquid-receiving bore 32.
With particular reference to FIGS. 5 and 6, the head 104 is slightly
thicker than the blade 102. The additional thickness of the head 104
provides additional rigidity, which is useful in locking the baffle 100
into position. In a constructed embodiment, the head 104 was three times
as thick as the blade 102, with the blade being centered on the head.
Particularly, the blade was 0.05" thick with a head 0.150" thick. Thus,
the head projected 0.05" on either side of the blade 102. of course, this
additional thickness of the head 104, although preferred, is not necessary
for operation of the baffle 100.
Referring to FIGS. 1 and 3 through 6, the baffle 100 creates turbulence in
the liquid flowing through the liquid-receiving bore 32 by use of plural
fins 106 projecting outwardly from respectively opposite faces 102A and
102B of the blade 102. The fins 102 create turbulence in the liquid
flowing through the liquid-receiving bore 32 by partially obstructing the
flow of liquid through the inlet passageway 32A and the outlet passageway
32B.
Referring particularly to FIG. 5, each fin 106 projecting from a face 102A
of the blade 102 is aligned longitudinally along the blade 102 with a fin
106 projecting from the opposite face 102B of the blade 102, and vice
versa, each of the fins 106 tapering or decreasing slightly in thickness
as it extends from a face 102. Preferably, the fins 106 are each
wedge-shaped, as best shown in FIGS. 3 and 6, but fins of other shapes may
be used without departing from this invention. With particular reference
to FIG. 3, each fin 106 has three margins, namely first and second linear
margins 108 and 110, respectively, and a third, outer margin 112, which
may be arcuate, as will be described below.
The first linear margin 108 of each fin 106 projecting from the face 102A
extends inwardly from a side edge of the blade 102 parallel with the face
102A and is connected thereto. The second linear margin 110 of each fin
106 extends outwardly from the face 102A of the blade 102. The third or
outer margin 112 of each fin 106 extends from the intersection of the
first linear margin 108 thereof with a side edge 114 of the blade 102 to
the second linear margin 110 thereof to form a wedge shape. Techniques for
molding the baffle 100 typically require the second linear margin 110 to
extend at an angle slightly less than normal to the face of the blade 102,
as shown in FIG. 6. For example, an angle of approximately 80 degrees has
been found to be acceptable to meet typical molding requirements.
The fins 106 projecting from the opposite face 102B of the blade 102 are
formed in a manner substantially identical to that described above with
regard to the fins 106 projecting from the face 102A of the blade 102.
With continued reference to FIGS. 3 through 6, the third or outer margin of
respectively aligned fins 106 on opposite faces of the blade 102 extend
from respectively opposite side edges 114 of the blade 102. In addition,
the fins projecting from a given face of the blade 102 are located at
mutually-spaced locations thereon, and the third or outer margins of
mutually-spaced, adjacent fins 106 on the given face of the blade 102
extend from respectively opposite side edges 114 thereof. In other words,
the third or outer margins of the fins 106 on a given face of the blade
102 extend from alternating side edges 114 thereof from one fin 106 to the
next.
Referring particularly to FIGS. 3 and 4, the first linear margin 108 of
each of the fins 106 extends inwardly from its respective side edge 114 of
the blade 102 across only a fraction of the width of the blade 102.
Preferably, this fraction is more than 1/2 of the width of the blade 102
so that little or no straight, continuous path is available for liquid
flowing through either the inlet passageway 32A or the outlet passageway
32B.
The illustrated baffle 100 includes seven fins 106 projecting from each
face 102A and 102B of the blade 102. The number of fins 106 projecting
from each face 102A and 102B may vary, depending on the length of the
blade 102. However, the longitudinal spacing between fins 106 is
preferably the same from one baffle to the next, regardless of the number
of fins 106, to permit water to flow around the fins 106. For example, a
longitudinal spacing of 0.39" has been found satisfactory in testing to
create sufficient turbulence in the liquid flowing through the
liquid-receiving bores 32. It is contemplated that baffles 100 of a single
length will be manufactured for several applications and that users will
cut the baffles 100 to the proper length for their application, depending
on the depth of the liquid receiving bores 32.
With reference to FIGS. 1 and 7, the liquid receiving bore 32 is typically
cylindrical, as a result of being formed by drilling. So that the baffle
100 fits snugly within the bore 32, the third or outer margin of each fin
is preferably convexly arcuate, as shown in FIGS. 3 and 6, to match the
curvature of the wall of the bore 32. When the baffle 100 is inserted into
the bore 32, the arcuate outer margins 112 of each fin engages the wall of
the bore 32 to not only provide a snug fit, but also to ensure that the
flow of liquid through the bore 32 is partially obstructed to create the
desired turbulence. In addition, the cylindrical bore 32 and the arcuate
outer margins 112 of the fins 106 facilitate rotation of the baffle 100
within the bore 32, for reasons which will be described below.
As best shown in FIG. 7, the liquid-receiving bore 32 typically has a
circular cross-section, although it may be of other geometric shapes. When
viewing the baffle 100 from an end, as in FIG. 6, a pair of adjacent fins
106 projecting from the face 102A of the blade 102 and the respectively
aligned fins 106 projecting from the opposite face 102B of the blade 102,
along with the blade 102, appear to substantially form a circle having a
diameter substantially equal to the diameter of the liquid-receiving bore
32. This is due, in part, to the arcuate outer margins 112 of the fins
106. Of course, the bore may have a geometric cross-sectional shape that
would require linear, rather than arcuate outer fin margins 112 to match
the cross-section of the liquid-receiving bore 32.
Referring now to FIG. 1, the head 104 of the baffle 100 is shaped and sized
to match the cross-section of the liquid conduit groove, including the
undercuts 30. Thus, the top or radially-outer portion of the head has side
margins which match the non-undercut portions of the liquid conduit groove
26. The bottom or radially-inner portion of the head 104 is wider than the
top portion of the head 104 to match the undercut portions of the groove
26, and has sloping side margins that conform to inwardly-facing surfaces
30A of the undercuts 30. The side margins of the head 104 slope at the
same angle as the undercuts relative to the groove sidewall 28. Because
the bottom portion of the head 104 matches the undercut portions of the
groove 26, the head 102 of the baffle 100 is wider, at least in part, than
the radially-outward opening of the liquid conduit groove.
With reference to FIGS. 8 and 9, a baffle 100 is assembled into the mold
insert 20 by first advancing the blade 102 of the baffle 100 into a
liquid-receiving bore 32 until the bottom surfaces of the baffle head 104
contact the bottom wall of the liquid conduit groove 26. Because the
baffle head is wider than the top or radially-outermost portion of the
groove 26, the baffle 100 must be advanced with the head 104 thereof
oriented to extend across the liquid conduit groove at an angle other than
ninety degrees relative to the groove sidewalls 28, as best shown in FIG.
8. For example, an angle of 45 degrees relative to the groove sidewall 28
is sufficient to permit the baffle head 104 to engage the bottom wall of
the groove 26. After the head 104 of the baffle 100 engages the base of
the liquid conduit groove 26, the baffle 100 may be rotated until the
baffle head 104 extends across the liquid conduit groove perpendicular to
the sidewalls 28 thereof, as shown in FIG. 9. This locates the baffle 100
as shown in FIG. 1.
Rotation of the baffle 100 to the position shown in FIG. 9 causes the
inwardly sloping side margins of the baffle head 104 to move under and
into locking engagement with the inwardly-facing surfaces 30A of the
undercuts 30 in the groove sidewalls 28. As a result, radial movement of
the baffle 100 from the liquid receiving bore is prevented. Frictional
engagement between the head 104 and the groove sidewalls 28, including the
undercuts 30, prevents rotation of the baffle 100. Thus, the baffle 100 is
locked in position within the liquid-receiving bore 32. When necessary,
the baffle 100 may be readily removed by performing the above-described
steps in reverse. For insertion and removal, the baffle 100 may be rotated
by hand or by use of a pliers-like gripping tool, such as common "needle
nose" pliers.
It is also contemplated that a baffle 100 may be locked into position in
the liquid conduit groove 26 by striking the baffle 100 with a suitable
tool, such as a rubber mallet or hammer (not shown). In this case, the
baffle 100 is inserted into a liquid-receiving bore 32 with the head 104
thereof oriented to extend perpendicularly across, but not in, the groove
26. A machinist or other person assembling the mold insert 20 would then
strike the head 104 of the baffle 100 with the rubber mallet or hammer to
advance the baffle 100 into the liquid-receiving bore 32 without rotation,
thereby causing the inwardly sloping side margins of the head 104 to snap
into place under and in engagement with the undercuts 30.
With reference to FIGS. 10 and 11, an alternate embodiment of the baffle
head is illustrated therein and generally designated 204. A baffle
utilizing the head 204 is assembled into the mold insert 20 in a manner
substantially identical to that described above with regard to the baffle
100 having a head 104. However, use of the alternate baffle head 204
provides improved locking characteristics, especially with respect to
rotational movement of the baffle 100.
The baffle head 204 is substantially identical to the baffle head 104
described above, except for the addition of hollowed-out portions or
recesses 206 provided therein. Four recesses 206A, 206B, 206C, and 206D
are provided, two in each face of the head 204 adjacent respectively
opposite side margins thereof. As evident from FIG. 11, the recesses 206A
and 206C are formed in one face of the head 204, and the recesses 206B and
206D are formed in the opposite face. The recesses 206 cause the outermost
portions of the head 204 to be resilient in that they spring back when
compressed.
FIGS. 12 and 13 illustrate two successive stages of the assembly of a
baffle 100 having a head 204 into the mold insert 20. In FIG. 12, the
baffle 100 has been rotated so that the head 204 thereof has just engaged
the sidewalls 28 of the liquid conduit groove 26. As the baffle 100 is
further rotated, as shown in FIG. 13, the material forming the baffle head
204 around the recesses 206A and 206B further engages the sidewalls 28 and
is pushed inwardly to compress around the recesses 206A and 206B. When the
baffle 100 is fully rotated to the orientation shown in FIGS. 9 and 14,
the resiliency provided by the recesses 206 clamps the baffle 100 into
place and inhibits rotation of the baffle 100.
With particular reference to FIG. 11, the recesses 206 each have a depth
substantially equal to half the thickness of the head 204. To avoid
creating slots or passageways through the head 204, the recesses 206A and
206C are offset from the recesses 206D and 206B, respectively. Without
this offset, passageways in the head 204 would be created by the recesses
206, and water flowing in the liquid conduit groove 26 would flow through
the passageways, which is undesirable.
Referring to FIG. 10, the head 204 has reliefs 208 at each margin of the
top thereof above the recesses 206. As the baffle 100 is rotated into
position, the material around the recesses 206 is likely to bulge
outwardly of the liquid conduit groove 26 as well as being compressed
around the recesses 206. The reliefs 208 permit such outward bulging to
occur without any part of the baffle 100 bulging above the raised center
of the head 204, as shown in FIG. 14. Thus, the baffle head 204 fits
entirely within the liquid conduit groove 26 when the baffle 100 is in
place within the groove 26.
As will be apparent to one skilled in the art, the above-described
techniques and construction for locking the baffle in place is equally
applicable to straight baffles and spiral baffles. In addition, one
skilled in the art will recognize that a single undercut 30 on one of the
sidewalls 28 may, in certain cases, be sufficient to retain the baffle
100. In such instances, the head 104 of the baffle 100 need have only one
inwardly sloping side margin movable into engagement with an undercut 30.
The opposite side margin of the head 104 may then conform to the opposite,
non-undercut side wall 28 of the groove 26.
One skilled in the art to which this invention pertains will also recognize
that baffles in accordance with this invention are useful in fields other
than injection molding to cool (or heat) solid components other than mold
inserts. In fact, baffles in accordance with this invention may be useful
in any situation where a solid component is to be cooled (or heated) by
liquid flowing through a liquid conduit therein. FIG. 15 illustrates a
threaded baffle 300 in accordance with this invention used to enhance the
cooling (or heating) of a generic solid component 302 having a liquid
conduit 304 passing therethrough for cooling (or heating) purposes and a
transverse bore 306 intersecting the conduit 304. In such instances, the
baffle 300 may be used in place of typical, prior art straight baffles or
spiral baffles. The baffle 300 may be secured in the bore 306 by any
suitable, known means, such as the illustrated threaded or so-called pipe
plug-type head 308 and tapped bore segment 310 or by press-fitting the
head into the bore, among other alternatives known in the art.
FIGS. 16 through 20 illustrate another embodiment of a baffle in accordance
with this invention, designated 400, which is a liquid barrier and may be
used in lieu of the dam or barrier 31 mentioned above. With particular
reference to FIGS. 16 and 17, the baffle 400 comprises a dam member 402
constructed to be substantially identical to the head 204 of the baffle
100, which is shown in detail in FIGS. 10 and 11. Therefore, like parts
and features are given like reference numbers. The dam member 402 could be
molded alone as described above with regard to the baffle 100 or it could
be formed by cutting away the blade of an existing baffle 100.
With particular reference to FIGS. 18 and 19, the dam member 402 is secured
in the liquid conduit groove 26 in the same manner as the baffle 100.
Particularly, the dam member 402 is located at the desired location within
the liquid conduit groove 26 and is then rotated to lock it into place. Of
course, the dam member 402 could also be configured as the head 104 of the
baffle 100 (FIG.3).
Although the presently preferred embodiments of this invention have been
described, it will be understood that within the purview of the invention
various changes may be made within the scope of the following claims.
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